Galanin is a polypeptide found in the central and peripheral nervous systems which regulates multiple processes such as endocrine and exocrine pancreatic secretions, intestinal motility, and modulation of behavioral, cognitive, and sensory functions such as feeding, learning, memory and nociception. See, e.g., Merchenthaler et al., Prog. Neurobiol. 40:711-769 (1993), and Hökfelt et al. in Galanin: A New Multifunctional Peptide in the Neuro-Endocrine System, Wenner-Gren International Symposium Series, 1991, Vol. 58, MacMillan, Cambridge, U.K. Because of its wide distribution and multiple activities, Galanin is believed to be involved in a number of medical conditions, including obesity, Alzheimer's disease, nociception, dementia, eating disorders, diabetes, dislipoproteinemia, developmental disorders of the neural systems, disorders of the digestive systems, growth disorders, sexual and reproductive dysfunctions, stomach ulcers, sleep disorders, and regeneration of injured neuronal systems.
The physiological effects of galanin are mediated by specific receptors in target tissues. One such receptor from insulin-secreting cells has been described by Lagny-Pourmir et al. [Endocrinology 124:2635-2641 (1989)]. Human galanin receptors have been cloned by Habert-Ortoli et al. [Proc. Natl. Acad. Sci. USA 91:9780-9783 (1994)], Hinuma et al. [European Patent Application Publication EP 0 711 830 A2] and Amiranoff et al. [International Patent Application Publication No. WO 95/22608].
In view of the important role of galanin in many physiological processes and medical conditions, there is a need for materials and methods for identifying selective agonists and antagonists of galanin.